The proposed study is a nonconcurrent follow-up of persons exposed to radium irradiation for treatment of enlarged adenoids. The main objective will be to determine the existence of any disease risks due to this low-dose radium exposure. The study population consists of 3220 individuals seen at an ear, nose and throat clinic in Washington County, Maryland, between 1943 and 1956, for symptoms related to enlarged adenoids. Approximately 880 of these individuals were exposed to radium irradiation. Both exposed and non-exposed persons will be followed to the present primarily for the development of benign and malignant neoplasms. Special attention will be paid to the development of thyroid and pituitary tumors and to the development of other thyroid and pituitary related disorders. Follow-up of all study subjects will be done through records available in Washington County, Maryland, including hospital records, death certificates, and the Washington County Hospital Cancer Registry. Additional follow-up of all 880 radium exposed and 880 non-exposed persons will be done with the use of a mailed health questionnaire.